Retro-claiming should actually work instantly and it does most of the time, especially when no changes were made to the original reservation, such as upgrades, re-bookings to other flights and/or other booking classes etc. etc.

The issue discussed here is a totally different one, where flights and miles have already gotten credited, but don't show up where they should be, except for the "transactions".

By the way, it's now been 1 week since I contacted Aegean about this (including sending them screenshots of everything) and it still hasn't been resolved for my wife's account.